print("不使用__slots__")
class MyClass(object):
    def __init__(self, name, identifier):
        self.name = name
        self.identifier = identifier
        self.set_up()
print("使用__slots__")
class MyClass(object):
    __slots__ = ['name', 'identifier']
    def __init__(self, name, identifier):
        self.name = name 
        self.identifier = identifier
        self.set_up()
